Synthesis and characterization of high performance Pt-(PrxCeyOz)/C catalysts for methanol electrooxidation

In this paper, PrxCeyOz (x/y = 3/1, 1/1, 1/3) modified Pt/C catalysts were prepared by wet precipitation and reduction method. The catalysts were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD) and energy dispersive X-ray analysis (EDX). TEM showed that Pt nanoparticles were uniformly dispersed on the surface of carbon support with an average particle size of 4.0–5.0 nm in the Pt-(PrxCeyOz)/C catalysts. XRD showed that all the Pt-(PrxCeyOz)/C catalysts displayed the typical character of Pt face centered cubic (fcc) phase. XRD and EDX analysis indicated that the rare earth oxides exist in an amorphous form. The Pt-(PrxCeyOz)/C electrocatalysts were compared with the Pt/C, Pt3-(PrOx)1/C and Pt3-(CeOx)1/C catalysts in terms of electrochemical activity and stability for methanol electrooxidation using cyclic voltammetry (CV) and chronoamperometry (CA) in 0.5 M H2SO4 + 0.5 M CH3OH solutions. The CO-tolerance experiment was measured in the CO-saturated 0.5 M H2SO4 solutions. The results showed that the Pt-(Pr1Ce1Oz)/C catalyst had the highest catalytic activity, the best stability and CO-tolerance, which could be used as a suitable electrocatalyst for direct methanol fuel cell.